Water tube boiler



Nov. 15, 1932.

H. E. YARROW WATER TUBE BOILER Filed Sept. 25, 1929 I 2 Sheets-Sheet 1raven-ion ww g yw L'Ill' X a ATTORNEY Nov. 15, 1932. H. E. YARROW WATERTUBE- BOILER Filed Sept. 25, 1929 2 Sheets-Sheet 2 ATTORNEY PatentedNov. 15, 1932 UNITED STATES HAROLD EDGAR YARROW, or GLASGOW, SCOTLAND,

WATER TUBE'BOILER Application filed September 25, 1929, Serial no.395,078, and in Great Britain October 12, 1928.-

This invention relates to water tube boilers in which the combustible,whether oil-or powdered coal, is injected into the combust on spacethrough a range of burners. V

5 This invention relates to water tube boilers fired with gas orpowdered coal, which are of the Yarrow type having banks of steamgenerating tubes connecting an elevated steam drum with water drums oneither side 9 of the combustion space and a superheater beyond one ofthese banks of generating tubes in the direction of flow of the furnacegases.

According to the present invention the range of burners by which thefuel is in- 5 jected into the combustion space situated between andbelow the banks of steam generating tubes is fitted in the side wall ofthe furnace which is situated below the water drum on the same side ofthe combustion space as O the superheater, so that the flames from theburners are directed away from the bank of water tubes on that side andtowards the other side of the combustion space and consequently musttraverse a long path before they encounter the superheater. By thisdisposition of the burners there is no possibility of any directimpingement of flame on the superheater tubes, although no baffles areinterposed between them and the combustion space and consequently thesuperheater may be worked at a temperature approximating to the safelimit to which the steel tubes constituting the superheater should beexposed.

The invention is illustrated in the accom panying drawings withreference'to a Yarrow marine boiler of the double flow type, Fig. 1being a side elevation and Fig. 2 a transverse section of such a boiler.

In these drawings A is the steam drum, B,

40 C and D the water drums, and E the superheater drum, F, G and H beingthe steam generating tubes and J the superheater tubes, which areacommodated in a space between the banks of tubes G and H.

The bank G of generating tubes in'front of the superheateris a narrowbank of unbafiled tubes of suflicient depth to lower the temperature ofthe furnace gases to the safe limit before theyreach the superheatertubes 0 J. The oil or other fuel is projected into the combustion spaceLi'na direction away from the bank of unbaflied, tubes G and towards theside of the furnace opposite to that on which the superheater issituated, a row of burners K being arranged in a side wall situatedbelow the superheater. With this arrangement of firing, the flames andhot Having thus described the nature of the said invention and the bestmeans I know of carrying the same into practical effect, I claim 1. Awater tube boiler of the Yarrow type, comprising an elevated steam drum,water drums disposed on each side of a combustion space, banks of steamgenerating tubes connectin said water drums to said steam drum andforming therebetween unbaffled passages for furnace gases from thecombustion space on each side of said space, a superheater situatedbeyond one of-said banks of steam generating tubes in the direction offlow of the furnace gases, a furnace wall situated below the water drumwith'which the last-named bank of steam generating tubes is connected,

arange of burners fitted in the said wall and directed away froms'aid'bank of tubes to.- vwards the opposite side of the combustionspace, and separate damper-controlled uptakes located on opposite sidesof the steam drum.

2. A water tube boiler of the Yarrow type, comprising an elevated steamdrum, a water drum disposed on one side of a combustion space, a pair ofwater drums disposed on the other side of said space, a bank of steamgenerating tubes connecting said steam drum with the first-named waterdrum, a lower bank of steam generating tubes connecting said steam drumwith one of said pair of water drums, an upper bank of steam generatingtubes connecting said steam drum with the other of said pair of waterdrums, a super- 2 I i J i,sss,15

heater situated in the space between the lower and the upper banks ofsteam generating tubes, the lower of said banks of steam gencratingtubes forming free u'n-bafiled passages therebetween from the combustionspace to the superheater space, a furnace wall situated below the waterdrum of the said lower bank of steam generating tubes, a range ofburners fitted in the said wall and 10 directed definitely away from thesaid lower bank of tubes and towards the opposite side of the combustionspace, and separate damper-controlled uptakes located on oppo" v sitesides of thesteam drum. In testimony whereof I have signed my name tothis specification."

HAROLD ILYARROW.

so I

